System and method for battery charging

Patent metadata

Field	Value
Publication number	US-2019143821-A1
Application number	US-201715813772-A
Country	US
Kind code	A1
Filing date	Nov 15, 2017
Priority date	Nov 15, 2017
Publication date	May 16, 2019
Grant date	—

Abstract

Methods and systems are provided for expediting charging of a battery before entry into a zero emissions zone. In one example, the battery is charged with a ratio of motor torque drawn from a first electric motor of an electric turbocharger and a second electric motor of an HEV driveline. The ratio is coordinated with adjustments to an exhaust waste-gate and an intake throttle so as to maintain operator torque demand and propel the vehicle while charging the battery.

First claim

1 . A method for a hybrid vehicle having a boosted engine, comprising:
responsive to anticipated vehicle operation in a low emission zone, charging a system battery via at least one of a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the charging of the system battery completed before the vehicle enters the low emission zone.

2 . The method of claim 1 , wherein the charging includes charging to a threshold state of charge, the threshold state of charge based on a duration and distance of vehicle operation until and within the low emission zone, wherein a rate of charge transfer during charging the system battery via at least one of the first electric motor and the second electric motor is higher than a rate of charge transfer to the battery during regenerative braking.

3 . The method of claim 1 , further comprising, while charging the battery, maintaining driver requested wheel torque based on operator torque demand via at least one of the first and the second electric motors.

4 . The method of claim 3 , further comprising selecting at least one of the first electric motor and the second electric motor based on each of operator torque demand and engine speed.

5 . The method of claim 4 , wherein the selecting includes:
while operating in a first low engine speed-load condition, selecting the second electric motor for charging the battery while maintaining wheel torque via an engine with the first motor disabled; while operating in a second low engine speed-high engine load condition, selecting the second electric motor for charging the battery while maintaining wheel torque via the engine with the first electric motor enabled; while operating in a third high engine speed-load condition, selecting each of the first and the second electric motors for charging the battery while maintaining wheel torque via the engine; and while operating in a fourth high engine speed-load condition, higher than the third high engine speed-load condition, selecting the first electric motor for charging the battery while maintaining wheel torque via the engine with the second electric motor disabled.

6 . The method of claim 5 , further comprising, while operating in the third engine speed-load condition, adjusting a split ratio of motor torque provided by the first electric motor relative to motor torque provided by the second electric motor for charging the battery based on one or more of boost pressure, a temperature of the first electric motor and the second electric motor relative to corresponding temperature thresholds, and a motor speed of the first electric motor and the second electric motor relative to corresponding speed thresholds.

7 . The method of claim 6 , wherein the adjusting includes charging the battery with a higher ratio of motor torque from the first electric motor relative to the second electric motor responsive to boost pressure being higher than a threshold pressure, the temperature of the second electric motor being higher than the corresponding temperature threshold while the temperature of the first electric motor is within the corresponding temperature threshold, or the motor speed of the second electric motor being higher than the corresponding speed threshold while the motor speed of the first electric motor is within the corresponding threshold.

8 . The method of claim 1 , wherein the second electric motor includes one of a crankshaft integrated starter motor and a propulsion motor coupled between an engine and a transmission in the driveline.

9 . The method of claim 1 , further comprising, while charging the battery via the first electric motor, decreasing an opening of a waste-gate coupled across an exhaust turbine of a turbocharger, and increasing an opening of an intake throttle coupled downstream of an intake compressor of the turbocharger.

10 . The method of claim 9 , wherein the opening of the waste-gate is decreased further as an amount of charge to be transferred to the battery increases, and wherein the opening of the intake throttle is increased as the opening of the waste-gate is decreased.

11 . A method, comprising:
while propelling a hybrid vehicle using engine torque, responsive to actual or imminent entry of the hybrid vehicle into a low emissions zone, providing an operator demanded torque by adjusting a waste-gate opening while charging a battery using a controlled ratio of motor torque from a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline.

12 . The method of claim 11 , further comprising selecting the ratio of motor torque based on the operator torque demand, the ratio of motor torque from the second electric motor increased as the operator torque demand increases.

13 . The method of claim 12 , further comprising, when the operator torque demand increases above a threshold, charging the battery using negative motor torque from the second electric motor while propelling the vehicle using engine torque in excess of the operator torque demand, the excess engine torque generated while providing positive motor torque from the first electric motor to the turbocharger shaft.

14 . The method of claim 12 , wherein as the ratio of motor torque from the first electric motor increases, the waste-gate opening is reduced beyond a position based on the operator demanded torque.

15 . The method of claim 12 , further comprising adjusting an intake throttle opening based on each of the waste-gate opening, the operator demanded torque, and the motor torque from the first electric motor.

16 . The method of claim 12 , wherein the ratio of motor torque is further selected based on amount and rate of charge transfer to the battery required before entry into the low emissions zone.

17 - 20 . (canceled)

21 . The method of claim 16 , wherein charging includes a threshold state of charge, the threshold state of charge based on a duration and distance of vehicle operation until and within the low emissions zone, wherein a rate of charge transfer during charging the battery via the first electric motor and the second electric motor is higher than a rate of charge transfer to the battery during regenerative braking.

22 . The method of claim 12 , further comprising selecting the ratio of motor torque based on engine speed.

23 . The method of claim 22 , wherein the selecting includes:
while operating in a low engine speed-load condition, selecting the second electric motor for charging the battery while maintaining wheel torque via an engine with the first electric motor disabled; while operating in a first high engine speed-load condition, selecting each of the first and the second electric motors for charging the battery while maintaining wheel torque via the engine; and while operating in a second high engine speed-load condition, higher than the first high engine speed-load condition, selecting the first electric motor for charging the battery while maintaining wheel torque via the engine with the second electric motor disabled.

24 . The method of claim 23 , further comprising, while operating in the first high engine speed-load condition, adjusting a split ratio of motor torque provided by the first electric motor relative to motor torque provided by the second electric motor for charging the battery based on one or more of boost pressure, a temperature of the first electric motor and the second electric motor relative to corresponding temperature

Assignees

• Ford Global Tech Llc

Inventors

• Bell David
• Buckland Julia Helen
• Kelly Tyler
• Stolzenfeld Timothy
• Xiao Baitao

Classifications

• B60W2556/50

  of positioning data, e.g. GPS [Global Positioning System] data · CPC title

• B60W2710/244

  Charge state · CPC title

• B60K2006/4825

  Electric machine connected or connectable to gearbox input shaft · CPC title

• B60W20/12

  using control strategies taking into account route information {(estimation or calculation of non-directly measurable driving parameters B60W40/00)} · CPC title

• B60W20/13

  in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion · CPC title